A paleomagnetic study of central Harrat Rahat, Western Saudi Arabia

Arabic Abstract

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English Abstract

Paleomagnetic results have been obtained from 23 sites in central Harrat Rahat, western Saudi Arabia. After averaging the site mean directions for the 8 normal polarity sites along with the antipoles of the 15 reversed polarity sites, the mean direction of magnetization has an inclination of 38.5 and declination of 353.2 with a₉₅ of 5.4. The late Pliocene-Pleistocene pole position is at Lat. 86.74⁰N, long. 345.49⁰E. Apparent polar wander path for Arabia shows divergence for Late Oligocene to Pleistocene time that is in good agreement with the opening of the Red Sea. A total of 92 NRM-TRM curves were determined by Thellier's method from all 23 sites. Most of them deviated from straight line of interest so much that reliable paleo-intensities determination could not be made. Observations of opaque mineralogy of magnetic carriers of the rocks indicate that samples with more oxidized titanomagnetite minerals are less susceptible to further alteration during heating.